纯javascript:为可拖动元素设置边框
你好 学习Javascript并尝试在容器中创建可拖动的元素 如何设置可拖动边框,使元素不能移出边框? 现在我有一个问题,当你把东西拖到底部或右边框时,元素会移出容器。 我的HTML如下所示:纯javascript:为可拖动元素设置边框,javascript,html,Javascript,Html,你好 学习Javascript并尝试在容器中创建可拖动的元素 如何设置可拖动边框,使元素不能移出边框? 现在我有一个问题,当你把东西拖到底部或右边框时,元素会移出容器。 我的HTML如下所示: <div id="container"> <div id="comboCon1"></div> <div id="comboCon2"></div> </div> 下面是关于MouseMove的事件: functi
<div id="container">
<div id="comboCon1"></div>
<div id="comboCon2"></div>
</div>
下面是关于MouseMove的事件:
function OnMouseMove(event) {
dragElement.style.left = Math.max(minBoundX, Math.min(offsetX + event.clientX - startX, maxBoundX)) + "px";
dragElement.style.top = Math.max(minBoundY, Math.min(offsetY + event.clientY - startY, maxBoundY)) + "px";
}
为了解决这个问题,css中有一点变化,因为您使用的是f position“relative”,将容器的偏移量指定给拖动的子容器
因此,在我的put drag元素处于绝对位置时,将offsetWidth更改为clientWidth,并且似乎可以工作(水平):
非常感谢,它确实有用!现在,我只需要理解clientWidth和offsetWidth之间的区别。在您的情况下,似乎没有影响,因为高度可以正常工作,并且它没有改变,用于offsetWidth。不同的值用于填充和/或不计算HtmleElement的宽度
function OnMouseMove(event) {
dragElement.style.left = Math.max(minBoundX, Math.min(offsetX + event.clientX - startX, maxBoundX)) + "px";
dragElement.style.top = Math.max(minBoundY, Math.min(offsetY + event.clientY - startY, maxBoundY)) + "px";
}
// Draggable Div 1
document.getElementById("comboCon1").style.position = "relative"; // -> Add position relative
document.getElementById("comboCon1").style.width = "151px";
document.getElementById("comboCon1").style.height = "10px";
document.getElementById("comboCon1").setAttribute("class", "draggable");
document.getElementById("comboCon1").style.border = "1px solid black";
document.getElementById("comboCon1").style.padding = "0px";
// Draggable Div 2
document.getElementById("comboCon2").style.position = "relative";
document.getElementById("comboCon2").style.width = "151px";
document.getElementById("comboCon2").setAttribute("class", "draggable");
document.getElementById("comboCon2").style.border = "1px solid black";
document.getElementById("comboCon2").style.padding = "10px";
// Container
document.getElementById("container").style.border = "1px solid black";
document.getElementById("container").style.width = "500px";
document.getElementById("container").style.height = "500px";
//////////////////////
// Begin Drag events
//////////////////////
var startX = 0; //-> Mouse position.
var startY = 0;
var offsetX = 0; // -> Element position
var offsetY = 0;
var minBoundX = 0; // -> Top Drag Position ( Minimum )
var minBoundY = 0;
var maxBoundX = 0; // -> Bottom Drag Position ( Maximum )
var maxBoundY = 0;
var dragElement; // -> Pass the target to OnMouseMove Event
var oldZIndex = 0; // -> Increase Z-Index while drag
// 1)
initDragDrop(); // -> initialize 2 Events.
function initDragDrop() {
document.onmousedown = OnMouseClickDown;
document.onmouseup = OnMouseClickUp;
}
// 2) Click on Element
function OnMouseClickDown(event) {
var target; // -> Element that triggered the event
if (event.target != null) { // -> If Browser is IE than use 'srcElement'
target = event.target;
} else {
target = event.srcElement;
}
// Check which button was clicked and if element has class 'draggable'
if ((event.button == 1 || event.button == 0) && target.className == "draggable") {
// Current Mouse position
startX = event.clientX;
startY = event.clientY;
// Current Element position
offsetX = ExtractNumber(target.style.left); // -> Convert to INT
offsetY = ExtractNumber(target.style.top);
// Border ( Div Container )
minBoundX = target.parentNode.offsetLeft; // Minimal -> Top Position.
console.log(target.parentNode.getBoundingClientRect(), target)
minBoundY = target.parentNode.offsetTop;
maxBoundX = minBoundX + target.parentNode.clientWidth - target.clientWidth; // Maximal.
console.log(maxBoundX, target.parentNode.clientWidth, target.clientWidth);
maxBoundY = minBoundY + target.parentNode.offsetHeight - target.offsetHeight;
oldZIndex = target.style.zIndex;
target.style.zIndex = 10; // -> Move element infront of others
target.style.position = 'absolute'
dragElement = target; // -> Pass to onMouseMove
document.onmousemove = OnMouseMove; // -> Begin drag.
document.body.focus() // -> Cancel selections
document.onselectstart = function () { return false }; // -> Cancel selection in IE.
}
}
// 3) Convert current Element position in INT
function ExtractNumber(value) {
var number = parseInt(value);
if (number == null || isNaN(number)) {
return 0;
}
else {
return number;
}
}
// 4) Drag
function OnMouseMove(event) {
dragElement.style.left = Math.max(minBoundX, Math.min(offsetX + event.clientX - startX, maxBoundX)) + "px";
dragElement.style.top = Math.max(minBoundY, Math.min(offsetY + event.clientY - startY, maxBoundY)) + "px";
}
// 5) Drop
function OnMouseClickUp(event) {
if (dragElement != null) {
dragElement.style.zIndex = oldZIndex; // -> set Z-index 0.
document.onmousemove = null;
document.onselectstart = null;
dragElement = null; // -> No more element to drag.
}
}